51000055 has 4 divisors (see below), whose sum is σ = 61200072. Its totient is φ = 40800040.

The previous prime is 51000049. The next prime is 51000071. The reversal of 51000055 is 55000015.

It is a semiprime because it is the product of two primes.

It is a de Polignac number, because none of the positive numbers 2^k-51000055 is a prime.

It is a super-2 number, since 2×51000055² = 5202011220006050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5100001 + ... + 5100010.

It is an arithmetic number, because the mean of its divisors is an integer number (15300018).

Almost surely, 2^51000055 is an apocalyptic number.

51000055 is a deficient number, since it is larger than the sum of its proper divisors (10200017).

51000055 is a wasteful number, since it uses less digits than its factorization.

51000055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10200016.

The product of its (nonzero) digits is 125, while the sum is 16.

The square root of 51000055 is about 7141.4322793120. The cubic root of 51000055 is about 370.8431102361.

The spelling of 51000055 in words is "fifty-one million, fifty-five", and thus it is an aban number and an uban number.